Flex Glue competes against JB Weld, Loctite, and Gorilla glue using wood, brick, PVC, and metal. Flex Glue and JB Weld are also used to glue an engine together. Will either product provide enough strength to allow the engine to run? Let's find out! I purchased all the products tested and I'm not sponsored by Flex, JB Weld, Loctite, Gorilla, or any other company or manufacturer. I do the best I can to provide unbiased and accurate testing.